Methods and apparatus for clamping tissue and occluding tubular anatomical structures

ABSTRACT

Apparatus and methods for occluding hollow body structures, such as blood vessels, and for attaching tissue layers together by providing implantable elements on opposite sides of the structure or tissue layers and drawing the implants together to occlude the body structure and/or bring the tissue layers together. The implants are deliverable in a low-profile configuration and self-expand to an enlarged configuration. The implantable elements are delivered by transfixing the body structure, then releasing the implants on opposite sides of the anatomical structure to urge the layers together to effect an occlusion or attachment. The implants are configured to apply oppositely directed forces to opposite surfaces of the tissue layers at alternate, circumferentially spaced locations and may constrain the tissue in a serpentine pattern or in a direct clamping pattern. The implants grip the tissue in a manner that defines a pressure zone about the transfixion aperture that prevents leakage from the aperture. The invention can be used to fasten tissue to non-tissue.

REFERENCE TO PENDING PRIOR PATENT APPLICATIONS

This patent application is a divisional application of pending U.S.patent application Ser. No. 15/699,975, filed Sep. 8, 2017 which is acontinuation of prior U.S. patent application Ser. No. 15/438,924, filedFeb. 27, 2017 which claims benefit of prior U.S. provisional patentapplication Ser. No. 62/408,426, filed Oct. 14, 2016 and which

-   -   (A) is a continuation-in-part of prior U.S. patent application        Ser. No. 14/639,814, filed Mar. 5, 2015 (now U.S. Pat. No.        9,936,955) which claims benefit of U.S. provisional patent        application Ser. No. 62/084,989, filed Nov. 26, 2014 which        -   (i) is a continuation-in-part of prior U.S. patent            application Ser. No. 14/272,304, filed May 7, 2014, (now            U.S. Pat. No. 10,076,339) which claims benefit of Prior U.S.            Provisional patent application Ser. No. 61/948,241, filed            Mar. 5, 2014 and Ser. No. 61/820,589, filed May 7, 2013            which            -   (a) is a continuation-in-part of prior U.S. patent                application Ser. No. 13/857,424, filed Apr. 5, 2013,                which claims benefit of prior U.S. provisional patent                application 61/620,787, filed Apr. 5, 2012 which                -   (1) is a continuation-in-part of prior U.S. patent                    application Ser. No. 13/348,416, filed Jan. 11,                    2012, which patent application claims benefit of                    prior U.S. Provisional Patent Application Ser. No.                    61/431,609, filed Jan. 11, 2011.

The disclosures of the eleven (11) above-identified patent applicationsare hereby incorporated by reference in their entireties as if fully setforth herein. Applicants claim priority to each of them.

FIELD OF INVENTION

The invention relates to methods and devices for the occlusion of bloodvessels and other hollow anatomical structures and for clamping tissuelayers together.

BACKGROUND

There are numerous medical conditions and procedures in which it isdesirable or necessary to occlude hollow or tubular body organs such as,for example, blood vessels or to clamp together layers of tissue or toclamp tissue to non-tissue material. One such example is in thetreatment of venous complications, such as varicose veins, in whichtreatment involves selective occlusion of the veins. Other ducts,vessels or hollow body organs also may have to be obstructed or tissuelayers clamped together for a variety of reasons. It would be desirableto provide devices and methods to effect occlusions of hollow bodyorgans and to secure tissue layers to each other in a manner that thatis easy and quick to apply.

SUMMARY

The present invention provides a new and improved minimally invasiveapproach for occluding tubular body structures such as, for example, fortreating varicose veins and other blood vessels where occlusion of thevessel or organ is an appropriate remedy.

More particularly, the inventions comprise the provision and use of anoccluder that is used to occlude a vessel so as to restrict blood flowthrough the vessel. It may be used, for example, to treat varicose veinsbelow the point of occlusion. Significantly, the device is configured tobe deployed using visualization as may be provided by ultrasound and/orother visualization apparatus (e.g., CT, MRI, X-ray etc.). As a result,the treatment may be provided in a doctor's office with minimal localanesthetic and effectively no post-operative care. The invention alsomay be utilized in other procedures under direct visualization (e.g.,during “open” surgery) or under indirect visualization such as duringlaparoscopic surgery where visualization is provided through the use ofa scope, or during percutaneous surgery where visualization is providedthrough the use of imaging apparatus such as an ultrasound imager, anX-ray imager, etc.

In one form of the invention, there is provided apparatus for occludinga blood vessel, the apparatus comprising: an occluder having twocooperative parts, each of which includes a plurality of legs configuredto assume (i) a diametrically reduced configuration for dispositionwithin the lumen of a tube, and (ii) a diametrically expandedconfiguration in which the legs are extended radially for dispositionadjacent to the blood vessel, such that when the two parts of theexpanded occluder are brought together in their diametrically-expandedconfiguration with the vessel between them so they can grip the vesselto occlude it. In one aspect of this form of the invention the legs ofthe two parts are in registry when they grip the vessel. In anotheraspect of this form of the invention, the legs of the two parts of theoccluder are interdigitated when they grip the vessel.

In another aspect of the invention, a method for occluding a bloodvessel is provided in which opposing walls of the vessel are clampeddirectly together and in which the clamping is effected directly along aplurality of radially extending lines that extend outwardly from theaxis of the occluder. In another aspect of the invention the opposingwalls are bought together by constraining them in a serpentine patterncharacterized by a series of reversing bends that extendcircumferentially about the occluder axis. In a further aspect of theinvention a clamping or occlusion device is provided in which the tissueis transfixed but in which leakage of fluids (e.g., blood) from thetransfixion puncture is minimized.

DESCRIPTION OF THE DRAWINGS

The various objects and advantages of the invention will be appreciatedfrom the following description with reference to the accompanyingdrawings in which:

FIG. 1 is an isometric illustration of the proximal and distal implantsof a two-part occluder of the invention with the legs of the implantsbeing in their relaxed, expanded configuration;

FIG. 2 is an isometric illustration of the distal implant with its legsexpanded;

FIG. 3 is an isometric illustration of the distal implant with thelocking tube removed;

FIG. 4 is an illustration of the locking tube;

FIG. 5 is an illustration of the distal implant partially collapsed;

FIG. 6 is an isometric illustration of the proximal implant with thelegs of the implants being in their relaxed, expanded configuration;

FIG. 7 is an illustration of the proximal implant with its legspartially collapsed;

FIG. 8 illustrates a delivery needle that may be used to deliver anddeploy the occluder;

FIG. 9 illustrates a distal implant delivery tube;

FIG. 10 illustrates a composite guidewire usable in deployment of theoccluder;

FIG. 11 illustrates, in larger detail, the distal end of the compositeguidewire;

FIG. 12 illustrates a guidewire rod component of the compositeguidewire;

FIG. 13 illustrates, in enlarged detail, the distal end of the guidewirerod;

FIG. 14 illustrates the guidewire sheath component of the compositeguidewire;

FIG. 15 illustrates, in enlarged detail, the distal end of the guidewiresheath;

FIG. 16 illustrates the pushrod of the delivery system;

FIG. 17 illustrates the proximal implant delivery tube;

FIGS. 18-41 are sequential, diagrammatic illustrations of the manner inwhich the two-piece occluder is delivered and deployed to occlude atubular vessel;

FIG. 42 is an isometric illustration of another embodiment of theinvention;

FIG. 43 is an exploded illustration of the embodiment of FIG. 42;

FIGS. 44 and 45 are diagrammatic illustrations of an occluder before andafter it has occluded a vessel;

FIG. 46 is an isometric illustration of another embodiment of theinvention;

FIG. 47 is a longitudinal sectional illustration of the embodiment ofFIG. 46 showing a ratcheting mechanism incorporated in the occluder;

FIGS. 48-50 are sequential illustrations of the manner in which theembodiment of FIGS. 46 and 47 may be employed to deliver and deploy anoccluder;

FIG. 51 is a diagrammatic illustration of an occluder in which webbingis carried by the legs of the implants;

FIG. 52 is a diagrammatic, plan view of an occluder as seen from theproximal side in which the legs of the proximal implant and distalimplant are in registry with each other so as to clamp directly tissueengaged between the proximal and distal implants;

FIG. 52A is a sectional illustration as seen along the circumferentialline 52A of FIG. 52 showing the manner in which the legs 235, 295 of theimplants are in registry and compress directly the opposing walls of anoccluded vessel;

FIG. 53 is an illustration similar to that of FIG. 52 but in which thelegs of the proximal and distal implants are interdigitated;

FIG. 53A is a sectional illustration as seen along the circumferentialline 53A of FIG. 53 showing the manner in which the interdigitated legs235, 295 of the implants are oriented and the manner in which theinterdigitated legs constrain the tissue layers in a series ofsequential, alternating and reversing serpentine bends;

FIG. 54 is a diagrammatic side elevation of the occluder in which thelegs of the implants are interdigitated and where the ends of the legsare overlapped;

FIG. 55 is a series of three photographs of a tubular vessel showing howthe occluder with interdigitated legs constrains the vessel to occludeit;

FIG. 56 is another illustration of an occluder showing a ratchetingmechanism;

FIGS. 57 and 58 illustrate an occluder and the manner in which therelative angular orientation of the proximal and distal legs can beadjusted;

FIG. 59 is a photograph of a histological section of a blood vesselillustrating the manner in which the vessel has been occluded by aninterdigitated occluder and after healing;

FIG. 60 illustrates, diagrammatically, multiple, single, separatepuncture placements of occluders for closing off a resected liver;

FIG. 61 Is a diagrammatic plan view of an occluder in which some of thelegs are wider or longer than others;

FIGS. 62 and 63 are diagrammatic illustrations of occluders with legs ofdifferent lengths and defining an oval region of compression;

FIG. 64 is an illustration of a distal implant with a plurality ofcircumferentially spaced tang-receptive windows of a modified lockingarrangement;

FIG. 65 is an illustration of a proximal implant with a plurality ofcircumferentially spaced window-engageable tangs of a modified lockingarrangement;

FIG. 66 is an illustration of the proximal and distal implants of FIGS.65 and 66 locked together;

FIG. 67 is another view of the engaged implants of FIG. 67;

FIG. 68 is a cut-away illustration of the engaged implants of FIGS. 65and 66;

FIGS. 69-72 are enlarged cross sectional illustrations of engagedproximal and distal implants with multiple windows and tangs showing themanner in which they engage each other;

FIGS. 73-77 illustrate the sequential deployment of the embodiment ofthe occluder of FIGS. 48-50; and

FIGS. 78-80 illustrate another embodiment of the invention.

ILLUSTRATIVE EMBODIMENTS

FIG. 1 shows an embodiment of a two-part occluder 200 formed inaccordance with the present invention. Two-part occluder 200 generallycomprises a distal implant 205 and a proximal implant 210. The occluderfunctions by compressing and securing the opposed walls of the vesseltogether. In one embodiment, distal implant 205, shown in further detailin FIGS. 2-6, comprises a body 215 comprising a tube 225 having a distalend 226, a proximal end 227, and a lumen 230. A locking tube 220 islocated within lumen 230 of the body 215. The tubular body 215 is slitintermediate its length so as to define a plurality of segments that,when the body is axially collapsed, will deform to define a plurality ofradially extending legs 235. Distal implant body 215 preferably isformed out of an elastic material (e.g., a shape memory material havingsuperelastic properties such as Nitinol or superelastic polymers,including superelastic plastics) and constructed so that the legs 235normally are bent and project laterally away from the longitudinal axisof tube 225 (e.g., in the manner shown in FIGS. 2 and 3). Due to theelastic nature of the material used to form distal implant body 215,legs 235 can be deformed to a tubular, substantially linear, low profileshape so that they can be constrained within the lumen of a deliverytube or needle. See, for example, FIG. 5, which shows legs 235 movedinwardly toward a low profile relative to the position shown in FIGS. 2and 3. However, when the constraint is removed, the elasticity of thematerial of the body 215 causes legs 235 to return to their relaxed,expanded position shown in FIGS. 43 and 44.

The lower, distal end 250 of the locking tube 220 is secured to thelower end of the body 215 as by spot welds applied via openings 270formed in the distal end 226 of distal body 215 so that distal body andlocking tube form a singular structure (see FIGS. 3 and 5). This enablesthe proximal end 227 of the tubular body 215 to move longitudinally in adistal direction along the locking tube. When distal implant 205 is inits substantially linear, low profile condition (i.e., with legs 235restrained in an in-line condition), distal implant locking tube 220terminates well short of tangs 240 formed in the distal implant body215, so that the proximal end 227 of distal implant body 215 can movelongitudinally relative to distal end 226 of distal implant body 215.

The distal implant includes an arrangement by which it can be locked inthe radially expanded configuration shown in FIG. 2. To that end,inwardly projecting tangs 240 are formed in tube 225 near the proximalend 227. Tang-receptive windows 265 are formed in the proximal region ofthe locking tube 220. The tangs and windows are positioned so that whenthe proximal end 227 of body 215 is moved distally a sufficient distanceto allow full radial expansion of legs 235 (see FIG. 1), locking tangs240 of distal implant body 215 will be received within windows 265 ofthe locking tube 220 to lock distal implant 205 in its radially-expandedcondition (FIGS. 2 and 3).

FIGS. 6 and 7 illustrate the proximal implant 210 that comprises a tube275 having a distal end 280, a proximal end 285, and a lumen 290 adaptedto receive the proximal end 227 of the tubular body 215 of the distalimplant 205. Tube 275 is slit at its distal end to define a plurality oflegs 295. One or more inwardly projecting tangs 300 are formed in tube275 adjacent its proximal end 285. Proximal implant 210 is preferablyformed out of the same or similar material as the distal implant and isconstructed so that its legs 295 normally project laterally away fromthe longitudinal axis of tube 275 (e.g., in the manner shown in FIG. 6).Legs 295 can be constrained inwardly to a low profile configuration sothat proximal implant 210 can assume a substantially linear dispositionto be contained within the lumen of a delivery tube. See, for example,FIG. 7, which shows legs 295 moved inwardly relative to the positionshown in FIG. 6. However, when the constraint is removed, the elasticnature of the material causes legs 295 to return to the expandedposition shown in FIG. 6.

The distal and proximal implants 205, 210 can be mated (with tube 225 ofdistal implant body 215 being received in lumen 290 of proximal implant210) so that the expanded legs 235 of distal implant 205 oppose and arein registry with the expanded legs 295 of proximal implant 210 (see, forexample, FIGS. 52 and 52A). That arrangement imposes a direct clampingaction on a blood vessel (e.g., vein) or other tissue disposed betweenthe registered legs to occlude the blood vessel. In that mode ofclamping the walls of the vessel are pressed together along a series ofcircumferentially spaced, radially extending lines. In another aspect ofthe invention, the proximal and distal implants may be arranged so thatthe legs of one are interdigitated with the legs of the other whichimposes a different, serpentine, clamping configuration. Interdigitationrefers to an arrangement that, when the proximal and distal implants areconnected the legs 295 of the proximal implant will overlie the spacesbetween the legs 235 of the distal implant (or vice versa), as discussedin further detail below. The distal implant 205 and proximal implant 210are configured to lock together in a clamped position by cooperativeengagement of tangs 300 of proximal implant 210 and tang-receptivewindows 245 of distal implant 205.

Two-part occluder 200 may be deployed using associated installationapparatus that comprises a hollow needle 305 (FIG. 8) for penetratingtissue, a distal implant delivery tube 310 (FIG. 9) that extends throughthe needle, for delivering distal implant 205 through hollow needle 305to the far side of the blood vessel which is to be occluded, a compositeguidewire 315 (FIGS. 10-15) having a selectively expandable distal tipfor providing support to various components during delivery anddeployment, and a proximal implant delivery tube 330 (FIG. 17) fordelivering proximal implant 210 and for mating with distal implant 205,as discussed below. The installation apparatus also may include aseparate tubular push rod 320 (FIG. 16) that is used in deployment ofboth the distal and proximal implants.

Hollow needle 305 (FIG. 8) has a distal end 335, a proximal end 340 anda lumen 345. Distal end 335 terminates in a sharp point 350. Hollowneedle 305 may comprise a side port 355 that communicates with lumen345. Distal implant delivery tube 310 (FIG. 9) has a distal end 360, aproximal end 365 and a lumen 370. Composite guidewire 315 (FIGS. 10-15)comprises a guidewire rod 370 and a guidewire sheath 380. Guidewire rod370 has a distal end 385 and a proximal end 390. Distal end 385terminates in an enlargement 395. Guidewire sheath 380 comprises adistal end 400, a proximal end 405 and a lumen 410 that receives theguidewire rod 370. The distal end 400 of guidewire sheath 380 has atleast one, and preferably a plurality of, proximally extending slits 415that are open on the distal end of guidewire sheath 380 and allow thedistal end of guidewire sheath 380 to expand radially when guidewire rod370 is urged proximally within the sheath 380. Tubular push rod 320(FIG. 16) has a distal end 420, a proximal end 425 and a lumen 430.Proximal implant delivery tube 330 (FIG. 17) has a distal end 435, aproximal end 440 and a lumen 445.

Two-part occluder 200 and its associated installation apparatus are usedas follows. First, hollow needle 305 carrying distal implant deliverytube 310 therein, which in turn contains the composite guidewire 315upon which is mounted distal implant 205 is passed through the skin ofthe patient, through intervening tissue, and across the blood vessel(e.g., vein 450) that is to be occluded (FIGS. 18-20). As this is done,any blood flowing out side port 355 can be monitored—excessive orpulsatile blood flow can indicate that hollow needle has accidentallystruck an artery. Next, hollow needle 305 is retracted, leaving distalimplant delivery tube 310 extending across the blood vessel (FIG. 21).The distal implant delivery tube 310 then is retracted partially toexpose the distal ends of composite guidewire and distal implant 205(FIG. 22). Next, push rod 320 is advanced over composite guidewire 315to advance the distal implant 205 and composite guidewire 315 out of thedistal end of distal implant delivery tube 310. As this occurs, legs 235of distal implant 205 are released from the constraint of distal implantdelivery tube 310 and its legs expand radially as shown in FIGS. 23 and24. Then, with push rod 320 being held in place against the proximal endof distal implant 205, composite guidewire 315 is expanded at its distalend and is pulled proximally so as to bring the distal and proximalimplants together until locking tangs 240 of distal implant body 215engage windows 265 of the locking tube 220, thus securing the expandedimplants together (FIG. 25). At this point, hollow needle 305, distalimplant delivery tube 310 and push rod 320 may be removed (FIG. 26),leaving distal implant 205 mounted on composite guidewire 315, with thelegs 235 fully deployed on the far side of the blood vessel and theproximal end of distal implant 205 extending into the interior of theblood vessel (FIG. 27). Thus, in the placement of the device the vesselor tissue is pierced (transfixed). Notwithstanding the transfixion, thelegs close the vessel or tissue to prevent flow and, therefore, there isno or minimal leakage of blood from the transfixion aperture. This maybe contrasted with use of staples or sutures to occlude vessels or clamptissue in which loss of blood through the puncture holes is a commonproblem.

With the distal implant so placed and deployed, the proximal implantdelivery tube 330 (carrying proximal implant 210 therein) is advancedover and along composite guidewire 315, until the distal end of proximalimplant delivery tube 330 sits just proximal to the blood vessel (FIGS.28-31). Push rod 320 then is used to advance the distal end of proximalimplant 210 out of the distal end of proximal implant delivery tube 330.As this occurs, legs 295 are released from the constraint of proximalimplant delivery tube 330 and open radially (FIGS. 32-35). Then, usingpush rod 320, proximal implant 210 is pushed distally along theguidewire as distal implant 205 is pulled proximally using compositeguidewire 315, the distal end of the guidewire sheath 380 being enlargedby enlargement 395. As distal implant 205 and proximal implant 210 aredrawn together, their legs 235, 295 cooperate to compress the bloodvessel, thereby occluding it. Distal implant 205 and proximal implant210 continue moving together until inwardly-projecting tangs 300 ofproximal implant 210 enter windows 245 of distal implant 205, therebylocking the two together as shown in FIG. 36. At this point push rod 320and proximal implant delivery tube 330 are removed. See FIG. 37. Next,composite guidewire 315 is removed by first advancing guidewire rod 370distally (FIG. 38) to enable the sheath to contract to its smallerdiameter. to a size smaller than lumen 262 in distal implant lockingtube 220. Guidewire sheath 380 and rod then can be withdrawn proximallythrough the interior of two-part occluder 200 (FIG. 39). The foregoingprocedure leaves two-part occluder 200 locked in position across theblood vessel, with the opposing legs 235, 295 compressing the bloodvessel, whereby to occlude the blood vessel. It should be understoodthat the composite guidewire 315 may take other forms that also serve todetachably bind to the distal implant such as, for example, providingthreads on the end of the guidewire to cooperate with a threaded recesson the distal implant to connect releasably the distal end of theguidewire to the distal implant.

In practicing the invention the legs of one or both of the implants maybe arranged to expand generally perpendicular to the axis of theoccluder or may be arranged to extend at an acute angle to thelongitudinal axis of the implant such that the legs on one or both ofthe implants collectively define a cone-like concave region (e.g., at301E in FIG. 44). The angle defined by the cone-like shape is referredto as the “cone angle” and may be varied to provide for different devicecharacteristics. The arrangement may be varied such that when bothimplants include legs defining the concave regions the concave regionsmay face each other (FIG. 42) or may face in the same direction (FIG.46) in a somewhat nesting configuration.

FIGS. 42-45 illustrate another form of the invention embodying anarrangement in which both the distal and proximal implants can be storedin and delivered through the same delivery tube or needle rather thanseparate proximal and distal implant delivery tubes. Additionally, thisembodiment illustrates a separate and alternative arrangement forsecuring the proximal and distal implants together. In this embodimentlocking tube 220E of the distal implant is provided with one or morelongitudinally spaced circumferential grooves or recesses 265E formedalong its length. As with the previously described embodiment, lockingtube 220E is secured at its distal end to the distal end of the distalimplant body 215E as by spot welding, adhesives, mechanical interlocks,etc. Instead of the arrangement of a composite guidewire to retain thedistal implant, the proximal end of the locking tube 220E also comprisesa first half 266E of a mechanical interlock by which the locking tube220E (and hence distal implant 205E) can be connected to a distalimplant retention tube 310E that has a mating second half 361E of themechanical interlock as described below. The mechanical interlockenables the distal implant to remain attached to the deployment deviceuntil the proximal implant has been deployed and secured to the distalimplant, as described below. As shown in FIGS. 48-50, the halves of theinterlock 266E comprise a stepped configuration 433E, 434E, they beingcomplementary so as to mate together. Although we have found that theconnection tends to stay together, a locking rod 436E may be passedthrough the interlock to further secure the connection. The rod must beremoved or withdrawn before separation of the interlock components.Alternatively, internal locking rod 436E may be replaced by an overtube(not shown) which telescopically projects over distal implant deliverytube 310E and distal implant locking tube 220E of distal implant 205E,whereby to enhance the connection between the members.

Locking tube 220E preferably is formed out of the same or similarmaterial as described above. By way of example but not limitation,distal implant locking tube 220E may be formed out of a titanium alloysuch as Ti 5 AL-4V or Nitinol.

In the embodiment of FIGS. 42-45 inwardly projecting tangs 300E areformed in tube 275E of the proximal implant for engaging the grooves orrecesses 265E in distal implant locking tube 220E. If desired, thelocations and configurations of grooves or recesses 265E and tangs 300Ecan be reversed, i.e., outwardly-projecting tangs 300E can be providedon locking tube 220E and grooves or recesses 265E can be provided on theinner side wall of tube 275E, or other means can be provided forconnecting tube 275E of proximal implant 210E to locking tube 220E ofdistal implant 205E. The positions of circumferential grooves orrecesses 265E of locking tube 220E and inwardly-projecting tangs 300E ofproximal implant 210E are coordinated so that when they engage legs 235Eof distal implant 205E and legs 295E of proximal implant 210E aresufficiently close to ensure adequate clamping of a blood vessel (orother tubular structure) disposed therebetween.

The manner in which the occluder 200E may be deployed is illustrated inthe context of a laparoscopic procedure using a laparoscopic device331E. A similar arrangement may be used for percutaneous delivery.First, hollow needle 305E containing both the distal and proximaldevices, longitudinally spaced within the needle lumen, is advanced tothe occlusion site, for example, while needle 305E is contained withinsheath 333E of the delivery device 331E (FIG. 73). In a percutaneousprocedure the needle would be inserted directly without a sheath. Thespacing between the implants within the needle is greater than thethickness of the vessel or tissue that is to be clamped. Then, sheath333E is retracted to expose the needle, e.g., by turning knob 334E andthe needle 305E is passed transversely through the walls of the bloodvessel (e.g., a vein) which is to be occluded or passed through tissueor objects to be secured to one another, such as a solid organ, orlayers of tissue, etc. At this point in the procedure, the implants arewithin the needle but on opposite sides of the vessel or tissue to beclamped. The distal implant is connected, at its mechanical interlock,to the distal end of the distal implant retention tube 310E. Theproximal implant is slidably disposed about the distal implant retentiontube 310E. Next, hollow needle 305E is retracted proximally, back acrossthe blood vessel, e.g., as by operating first trigger 336E (FIG. 73) toprogressively expose the distal implant and to allow legs 235E of distalimplant 205E to expand radially on the far side of the blood vessel. Thedistal implant is held in place by its connection with the retentiontube. At this point, distal implant locking tube 220E extends proximallythrough the blood vessel.

Then, with retention tube 310E held in place, hollow needle 305E iswithdrawn further proximally (e.g., via first trigger 336E) untilproximal implant 210E is exposed and is no longer constrained withinhollow needle 305E (FIG. 74). As this occurs, legs 295E of proximalimplant 210E are released fully from the constraint of hollow needle305E and open.

Proximal implant delivery tube 330E then is advanced distally along andabout the retention tube 310E, (e.g., using second trigger 337E), topush the proximal implant 210E toward distal implant 205E (FIG. 75). Asdistal implant 205E and proximal implant 210E are drawn together, theirlegs 235E, 295E compress the blood vessel therebetween, therebyoccluding the blood vessel. Distal implant 205E and proximal implant210E continue moving together until inwardly-projecting tangs 300E ofproximal implant 210E enter circumferential grooves or recesses 245E ofdistal implant 205E, thereby locking the two members into positionrelative to one another. Proximal implant delivery tube 330E iswithdrawn (FIG. 76), retention tube 310E is released from distal implant205E (i.e., by using lever 338E) to unlock the second half 361E of themechanical interlock from the first half 266E of the mechanicalinterlock, and then the installation device is withdrawn (FIG. 77).

The foregoing procedure leaves two-part occluder 200E locked in positionacross the blood vessel, with the opposing legs 235E, 295E compressingthe blood vessel therebetween, whereby to occlude the blood vessel.

In the preceding disclosure, two-part occluder 200E is discussed in thecontext of using the elasticity of its legs 235E, 295E to cause its legs235E, 295E to reconfigure from a diametrically reduced configuration(e.g., when constrained within a delivery needle) to a diametricallyexpanded configuration (e.g., when released from the constraint of adelivery needle). However, it should also be appreciated that where legs235E, 295E are formed out of a shape memory material (e.g., Nitinol), atemperature change may be used to reconfigure legs 235E, 295E from adiametrically-reduced configuration to a diametrically-expandedconfiguration. By way of example but not limitation, in this form of theinvention, legs 235E, 295E may be constructed so as to have adiametrically reduced configuration when maintained at a temperaturebelow body temperature, and legs 235E, 295E may be constructed so as tohave a diametrically expanded configuration when maintained at bodytemperature. As a result, by cooling two-part occluder 200E to atemperature below body temperature, inserting the two-part occluder intothe body, and then allowing the two-part occluder to heat to bodytemperature, legs 235E, 295E can be caused to reconfigure from theirdiametrically-reduced configuration to a diametrically-expandedconfiguration.

Although the system has been described primarily in connection with apercutaneous delivery device, the installation apparatus can be adaptedfor use in laparoscopic, endoscopic or open surgical procedures, as byassociating the components of the delivery system (a hollow needle,distal implant delivery tube, a composite guidewire or equivalent, atubular push rod and a proximal implant delivery tube) with anappropriate handle at the proximal end of the system for controlling theoperation of the components.

Although the two-part occluders discussed above rely on thesuperelasticity of the material to cause the legs of the implants toself-expand when released from the delivery tube, it should also beappreciated that where legs 235E, 295E are formed out of a shape memorymaterial (e.g., Nitinol), a temperature change may be used toreconfigure legs 235E, 295E from a low profile, diametrically reducedconfiguration to a diametrically expanded configuration. By way ofexample but not limitation, in this form of the invention, legs 235E,295E may be constructed so as to have a diametrically reducedconfiguration when maintained at a temperature below body temperaturebut to have a diametrically expanded configuration when maintained atbody temperature. As a result, by cooling two-part occluder 200E to atemperature below body temperature, inserting the two-part occluder intothe body, and then allowing the two-part occluder to heat to bodytemperature, legs 235E, 295E can be caused to reconfigure from their lowprofile, diametrically reduced configuration to a diametrically expandedconfiguration.

FIG. 46-47 show another two-part occluder 200E similar to that describedabove except that legs 235E of distal implant 205E, and legs 295E ofproximal implant 210E, have their concavities facing in the samedirection, so that legs 235E, 295E nest with one another rather thanconfront one another. In addition, as seen in FIGS. 46-47, tube 225E ofdistal implant 205E is partially received in lumen 290E of proximalimplant 210E.

FIGS. 48-50 illustrate the releasable mechanical interlock forconnecting the distal implant to distal implant retention tube 310E. Asshown in FIGS. 48-50, the first half 266E of the mechanical interlockcarried by the proximal end of locking tube 220E comprises a steppedconfiguration 433E, and the second half 361E of the mechanical interlockcarried by the distal end of distal implant delivery tube 360E comprisesa mateable, complementary stepped configuration 434E. With thecomplementary parts engaged, the connection may be secured by placing alocking rod 436E through central lumen 437E of distal implant retentiontube 310E and into lumen 262E of implant locking tube 220E.Alternatively, in another form of the invention, internal locking rod436E may be replaced by an overtube (not shown) that can be placed overthe engaged distal implant retention tube 310E and locking tube 220E toprevent, temporarily, their separation.

It should also be appreciated that other forms of temporary mechanicalinterlocks may be used for releasably securing distal implant 205E ofthe two-part occluder 200E of FIGS. 46 and 47 to distal implantretention tube 310E. By way of example but not limitation, a screwinterlock may be used, e.g., the first half 266E of the mechanicalinterlock (carried by the proximal end of distal implant locking tube220E) may comprise a threaded bore, and the second half 361E of themechanical interlock (carried by the distal end of distal implantdelivery tube 360E) may comprise a threaded post, wherein the threadedpost carried by the distal end of distal implant delivery tube 360E maybe received in the threaded bore of distal implant locking tube 220E.Alternatively, other configurations of a screw interlock may be used, orother forms of mechanical interlocks may be used. In still anothervariation the locking tube 220E can be formed integral with distalimplant retention tube 310E, with a weakened section disposed at theirintersection, and with the two members being separable a mechanicalbreaking action.

It will be appreciated that, in certain circumstances, it may bedesirable to increase the surface area of those portions of the occluderthat contact the tubular body structure, in order to better distributethe load applied to the tissue. In this situation, it can be helpful toincrease the width of the legs (e.g., legs 235E and/or legs 295E oftwo-part occluder 205E, etc.), and/or to provide flexible material inthe zone between adjacent legs (e.g., in the manner of an umbrella) sothat the flexible material can also carry load (i.e., essentiallyincreasing the effective width of legs 235E and/or legs 295E). See, forexample, FIG. 51, which shows flexible material 438E extending betweenlegs 235E and legs 295E.

The relative orientation of the legs of the proximal and distal implantsmay be selected to provide different clamping patterns, the selection ofwhich may depend on the particular anatomy and characteristics of thetissue with which it is to be used. In one configuration, as describedabove and as shown diagrammatically in FIGS. 52A and 52B, the legs 295of the proximal implant are arranged to be in registry with some or allof the legs 235 on the distal implant such that pairs of proximal anddistal legs 295, 235 will cooperate to directly compress the vessel orother tubular body structure or tissue along a series of angularlyspaced, radial extending clamping lines CL as suggested diagrammaticallyin FIG. 52. It may be noted that although the direct clamping tends tocause the opposing walls of the vessel to contact each other between theclamping lines as well as along the clamping lines CL, in some casesdirect contact may not occur in one or more regions between the clampinglines CL. However, even where some such regions may exist, thearrangement of multiple, angularly spaced direct clamping lines provideenough obstruction to the lumen to cause effective occlusion.

FIGS. 53 and 53A illustrate another arrangement of the legs 295, 235 ofthe proximal and distal implants in which the legs are interdigitated sothat they do not effect a direct clamping of the tissue but, instead,engage the tissue to constrain the tissue in a serpentine configurationextending at least partly about the axis of the occluder in a generallycircumferential direction. In an interdigitated arrangement, the legs ofone of the implants are out of registry with those of the other implantso that when viewed in plan, the legs of one implant lie between thelegs of the other. In particular, arranging the legs in aninterdigitated array is considered to allow a tubular structure to besafely occluded in a way that avoids leakage problems associated withstaples or conventional clips (e.g., hemoclips, Ligaclips, etc.). In aninterdigitated configuration the opposing walls of the vessel aretogether partially wrapped about the legs in alternating directions toconstrain the tissue in a serpentine configuration as seendiagrammatically in FIG. 53A. Additionally, interdigitation provides anadditional means by which the clamping forces can be adjustablycontrolled. By selecting a particular cone angle defined by the expandedlegs, coupled with the dimensions and positioning of the mechanicallocking mechanism by which the relative position of the legs of thedeployed occluder are determined, the characteristics of the serpentinepattern can be determined. Cone angle selection also may be used tocontrol the degree of compression between the legs of the implants inthe direct clamping embodiment of FIGS. 52, 52A.

FIG. 54 shows a two-part occluder 200 and illustrates further the mannerin which the legs 295 of the proximal implant 210 are interdigitatedwith the legs 235 of the distal implant 205. When interdigitated, theouter free ends of the legs of each, in the absence of engaged tissue,intersect a plane defined by the free ends of the other, a conditionthat may be referred to as “overlap”. If desired, the degree of overlap(and, therefore, the degree of interdigitation) may be designed into thedevice by selecting the cone angle for the legs and the location of thelocking mechanism for the implants.

Another variable that may be used to control the manner in which theoccluder engages the tissue is to vary the angular offset between thelegs of the proximal and distal implants. Variable offset between legs235 and legs 295 allows for the adjustment of clamping tension appliedto the tissue. For example, for delicate or easily damaged or torntissue (e.g., brain tissue), or tissue that has limited elasticity, itis believed to be generally preferable that legs 235 and legs 295 areout of alignment to constrain the tissue in serpentine pattern(interdigitation) so that no direct compression is applied to thetissue. The cooperative tangs and windows or detents and grooves 265 maybe arranged to provide for a selected degree of overlap andinterdigitation. In the arrangement of tangs and windows there may beone or several circumferentially spaced windows by which the angularorientation of the legs of the implants can be varied when locked.

FIG. 55 shows three photographs of a two-part occluder 200 withinterdigitated legs effectively clamping a simulated blood vessel. Theinterdigitated legs cause serpentine ripples, or folds, in the tissuethat act to extend the effective closure, and causes closure of thevessel well beyond the region directly contacted by the occluder legs235, 295. This is believed to result because the serpentine patternextends radially somewhat beyond the periphery defined by the implantlegs. By way of example but not limitation, a two-part occluder 200having a physical occlusion diameter of 5.5 mm is able to close vesselsthat are over 7 mm (and even equal or greater than 1 cm) in diameter.

It should be understood that when an interdigitated device is lockedinto engagement with tissue, the thickness or nature of the tissue maycause the legs to flex to an extent that the degree of overlap isreduced or the legs may no longer overlap at all. Even when this occursthe legs of the proximal and distal implants still apply forces to thetissue that alternate in proximal and distal directions with the legs ofthe proximal implant applying distally directed forces and the legs ofthe distal implant applying proximally directed forces. These opposedforces of the implant legs, applied alternately at circumferentiallyspaced locations about the center of the occluder, are effective tosecure tissue layers together or to occlude a lumen.

Additionally, we have found that even when the legs of the proximal anddistal implants are initially in registry, when the implants are urgedtogether and locked in very close proximity to each other, the initiallyregistered legs can flex into a non-registered configuration in whichthe legs may be interdigitated and/or may apply oppositely directedforces to the tissue at circumferentially spaced locations about thecenter of the occluder as described above,

The legs 295, 235 of the proximal and distal implants 210, 205 may bebeveled (or rounded) so that they do not present sharp edges, and legs295, 235 may be designed to separate slightly from the tissue at thefree end of each leg. This is in order to minimize any catching ordamage that may be imparted on the tissue by legs 235, 295, whereby tominimize tearing or ripping of the tissue. In other embodiments of thepresent invention, it may be desirable to provide sharp features to legs235, 295 so that legs 235, 295 catch or pierce the tissue for bettergripping. Legs 235, 295 may be provided with smooth surfaces or may beroughened, as by chemical etching or mechanical means, so as to enhancethe imaging reflectivity of the implants, or to provide increase tissuecapture and gripping.

The two-part occluder as described may be configured to occlude bloodvessels under fluid pressures of at least 100 mm Hg and up to 300 mm Hg.Occluders also may be made that are capable of resisting pressure ofover 700 mm Hg.

FIG. 56 shows one embodiment of the present invention wherein distalimplant locking tube 220 comprises a controllable ratcheting mechanismfor selectively controlling the spacing between proximal implant 210 anddistal implant 205 when they are secured together. In this form of theinvention, legs 235 of distal implant 205 and legs 295 of proximalimplant 210 may be generally oriented primarily in a parallel registeredorientation to each other. In this form of the invention, locking tube220 comprises a plurality of windows 265 (or circular grooves) formedalong its length. Proximal implant 210 comprises one or more inwardlyprojecting tangs 300 formed at a point along its length. As proximalimplant 210 is advanced distally towards distal implant 205, inwardlyprojecting tangs 300 enter into windows 265, thereby locking proximalimplant 210 to distal implant 205. Inwardly projecting tangs 300 areconfigured so that proximal implant 210 can only move in a singledirection (i.e., distally) relative to distal implant 205. As proximalimplant 210 is advanced distally relative to distal implant 205,inwardly projecting tangs 300 can slide out of windows 265 and enter thenext distal window 265. If desired, windows 265 may comprise a chamfereddistal edge to facilitate movement of inwardly projecting tangs 300 outof windows 265 as proximal implant 210 moves distally relative to distalimplant 205. FIG. 56 shows another variation in which the“notch-to-notch distance” (i.e., the distance between windows 265)governs the ability to vary the degree of compression establishedbetween legs 235 of distal implant 205 and legs 295 of proximal implant210.

FIGS. 57 and 58 illustrate the a manner in which the rotationalorientation of the proximal and distal implants and, therefore, theirrespective legs may be set. In the example shown, one or more alignmentgrooves (or notches) 605 may be formed in the proximal end of proximalimplant 210, and one or more corresponding orientation alignment post(or tab) 610 may be formed in the distal end of the pusher tube forselective engagement with the grooves or notches 605. The relativeorientation of the proximal implant 210 and the distal implant 205 thuscan be varied by selectively engaging the grooves and posts and rotatingthe proximal implant relative to the distal implant until the desiredangular orientation is achieved. The procedure can be done undervisualization as described above. Alternately, the relative orientationmay be adjusted by using the retention tube to rotate the distal implantrelative to the proximal implant.

In another modification, the orientation of the legs can bepredetermined by providing a slot and groove arrangement between theproximal and distal implants to assure that they can be locked togetheronly in a desired relative angular orientation. Thus the disposition oflegs 235 of distal implant 205 relative to the disposition of legs 295of proximal implant 210 may be controlled so as to apply a desiredclamping force according to the type and/or condition of the tissue thatis to be clamped.

When the two-part occluder is arranged with its legs interdigitated, thewall thickness of the vessel to be occluded or the tissue layers to bejoined does not necessarily determine whether an effective occlusion orattachment can be achieved. As long as the interdigitation of the legsconstrains the vessel walls in a serpentine pattern or the forces arealternately applied in proximal and distal directions circumferentiallyabout the center of the occluder the walls of the vessel will may bebrought into contact with each other sufficiently to occlude the vessel,even when the legs 235 and legs 295 may not cross each other's plane(“overlap”) regardless of the summed wall thickness of the vessel. Thus,vessels, of varying dimensions can be effectively occluded. Whether andto what extent the legs of the proximal and distal implants may overlapwill depend on the characteristics and dimensions of the anatomy to beoccluded and the configuration for the implants necessary to constrainthe tissue in a serpentine configuration.

Where legs 295, 235 of the proximal and distal implants 210, 205 areinterdigitated, the serpentine constraint of the tissue layers reducesthe force needed to occlude the vessel and is considered to be much lessthan the force needed to close the same vessel with a conventionalligation clip. FIG. 59 is a photograph of a histological section oftissue from a vessel occluded with an interdigitated occluder andshowing the serpentine pattern of the tissue layers of the vessel wallsafter healing of up to 30 days. The vessel is completely occluded andthe vessel wall tissue is compressed and adhered to itself in theserpentine configuration. The “pie crust” or serpentine closure may beobserved more clearly as well. The arrow indicates the collapsedundulating artery. AVO indicates the location of the interdigitatinglegs of two-part occluder 200.

The two-part occluder 200 of the present invention may be used toocclude vessels, ducts and/or to compress tissue so it isoccluded/compressed at forces less than 700 grams, while the forcerequired to seal off vessels or clamp tissue with a commerciallyavailable Ligaclip are about ten times greater. The two-part occluder200 of the present invention can maintain operation within the range ofelasticity of the material and does not need to be plastically deformedto realize occlusion.

It will be appreciated that the occluder of the present invention canalso be used to occlude tubular and hollow structures other than bloodvessels. By way of example but not limitation, the temporary occluder ofthe present invention can be used to occlude fallopian tubes, vasdeferens, ducts, as the bile duct and cystic ducts for cholecystectomy,lymphatic vessels, including the thoracic duct, fistula tracts, etc. Thepresent invention can also be used to bring, attach and/or connect atleast two folds (e.g., two sides of the stomach, or other parts of thelegs, etc.) together so that they are connected.

In addition to occluding blood vessels the occluders can be used forclamping and compressing regions of resected organs so as to reduce orstop blood flow or blood loss after surgery. For example, as shown inFIG. 60 the occluder may be used in solid organ resection of the kidneyor liver or other organs. Blood loss and secretion leakage (e.g., bile,urine, etc.) can be problematic in existing solid organ resectionprocedures. Average blood loss for a liver resection is 700-1200 ml. Byclamping desired regions of the solid organ with one or more occluders,it is possible to significantly reduce the amount of undesirable fluidloss (blood loss, secretion leakage, etc.). The occluder can be used toapply pressure selectively to broad areas of the organ and,additionally, may also be used to close off selective tubular structuresand vessels connecting the organ with other regions of the body.Multiple discrete occluder elements may be deployed across regions ofthe organ as suggested in FIG. 60. Where multiple, single, separatepuncture placements of the occluder are used, different regions of thesolid organ may be compressed to different and controllable degrees.

Although described in the context of occluding blood vessels, thepresent invention may be practiced under direct visualization (e.g.,during “open” surgery) or under indirect visualization (e.g., duringlaparoscopic surgery where visualization is provided through the use ofa scope, or during percutaneous surgery where visualization is providedthrough the use of imaging apparatus such as an ultrasound imager, anX-ray imager, etc.).

The present invention can be used for occlusion of tubular structuressuch as veins, arteries, bile ducts, fallopian tubes, cystic ducts, etc.

The present invention can also be used to connect tissue with othermaterials, e.g., graft materials, hernia meshes, drug deliverymaterials, etc.

FIG. 61 shows a two-part occluder 200 and its surrounding effectivepressure zone. Note that the different overlaps between legs 295 ofproximal implant 210 and legs 235 of distal implant 205 are controllablyadjustable to provide the desired pressure zone and occlusion level. Thelegs also may be formed to have different and varying widths.

In one form of the present invention, the pressure zone (the area inwhich the tissue layers are urged into contact) generated by two-partoccluder 200 is a generally circular area extending around the entrypoint of the transfixing distal locking tube 220 (FIG. 62), but in otherembodiments the pressure zone may be non-circular, meaning that thelengths of legs 235 of distal implant 205 and legs 295 of proximalimplant 210 are not equal. For example, an oval pressure zone may beemployed with legs of unequal or asymmetric length, so that the occluder200 can be positioned proximal to a branched vessel or tissue, as shownin FIG. 63. In one form of the present invention, the orientation of theproximal and distal implants of two-part occluder 200 can be determinedusing markings disposed on the delivery device handle (e.g., an arrowwhich indicates the long direction of legs 235, 295). In laparoscopic oropen procedures, the orientation of two-part occluder 200 can also bevisually confirmed. In percutaneous applications, ultrasound, or CTimaging can be used to further determine orientation of two-partoccluder 200 relative to vessels, ducts, organs, tissue that is are tobe clamped or occluded.

FIGS. 64-72 illustrate the components of a modified occluder having alocking mechanism of tangs and windows that assures locking of theimplants when they are brought together, regardless of theirorientation. In this arrangement the distal implant can be laser cutwith one or more windows circumferentially spaced about the hollowtubular section of the implant. The mating proximal implant can be cutto include one or more tangs, each tang configured to engage a window,thereby locking the two occlusion elements together. In the embodimentof FIGS. 64-72, the tangs and windows are designed to lock togetherregardless of the angular orientation of the legs of the implants (afeature referred to as “angular relation indifference.”

FIG. 64 shows a distal implant 722 with three windows 771 (only twovisible) that are spaced evenly around the circumference of theocclusion element 722, located proximal to the legs. A portion 775 ofthe tube separates and frames each pair of adjacent windows 771. In theembodiment shown, each of the three windows 771 occupies approximately80 degrees of the circumference of the tube, and each window frameportion 775 occupies approximately 40 degrees of the circumference ofthe tube. It should be understood that other arrangements and sizes ofwindows are possible that will still achieve the angular relationindifference configuration.

FIG. 65 shows a proximal implant 724 with four inwardly projecting tangs781, only two of which are visible in the drawing. Despite the differentnumbers of windows 771 and tangs 781, FIGS. 66-72 illustrate how thedistal implant 722 and the proximal occlusion element 724 will locktogether, regardless of their angular orientation. FIG. 66 shows theproximal implant 724 and the distal implant 722 locked together. Thedistal implant 722 has a smaller diameter than the proximal implant 724and fits within the hollow tube of the proximal implant 724. The twovisible tangs 781 a and 781 b are both projecting inwardly into thecorresponding windows 771 of the distal implant 722, thereby lockingthem in place. FIG. 67 shows a side view to more clearly show theinwardly projecting tangs 781 a and 781 b locked in place with respectto the windows 771.

FIG. 68 shows a sectioned view of the two implants locked together. Dueto the different configurations of the tangs 781 and windows 771 (i.e.,there are four tangs 781 a-d but only three windows 771 a-c), tangs 781c and 781 d do not project into the windows 771 in the orientationshown. However, regardless of orientation of the two occlusion elements,at least one (and as many as two) of the four tangs will always belocked in place. That angular relation indifference is shown moreclearly in FIGS. 70-72.

FIG. 69 shows a close-up cross-section view of the two implants lockedtogether. In this orientation, tang 781 a is locked in place in thewindow 771 defined by window frame elements 775 a and 775 b; and tang781 b is locked in place in the window 771 defined by window frameelements 775 a and 775 c. Tangs 781 c and 781 d are not projecting intowindows, but are instead contacting window frame elements 775 b and 775c, respectively. FIG. 70 shows a slightly different orientation betweenthe two elements. This orientation is rotated clockwise from theorientation shown in FIG. 70. In FIG. 70, tangs 781 b and 781 c projectinto windows 771 framed by elements 775 a and 775 b, and 775 b and 775c, respectively. Tangs 781 a and 781 d are in contact with window frameelements 775 a and 775 c, respectively. FIGS. 71 and 72 show two otherorientations, with the proximal occlusion element 724 rotated clockwisewith respect to the preceding orientation. Regardless of how manydegrees the proximal occlusion element 724 is offset from the distalocclusion element 722 (from 0-360 degrees), in any orientation therewill always be at least one, and as many as two, of the tangs lockedinto one of the windows, due to the angular relation indifferenceconfiguration.

The tangs and windows may be configured to control the relative angularposition of the legs of the proximal and distal implants. For example,the windows and tangs may be configured to engage only when the legs ofthe two implants are oriented in a specific angular relation. Thus, thelegs of a distal occluder can be offset with respect to those of theproximal occluder to achieve an interdigitating configuration asdiscussed above. In other embodiments, it may be desirable for the legsto align so as to compress the structure between aligned legs. Otheralignments may be preferable as well, including partially offset legs.

FIGS. 78-80 illustrate, diagrammatically, another type of occluder 800that may be formed from a wire of shape memory material, such as Nitinoland constrains the tissues in a serpentine pattern. The wire can bedelivered through a needle or other delivery tube that is first advancedthrough the walls of the vessel or tissue layers, as described below.The wire may be maintained in a linear configuration by the lumen of theneedle or delivery tube but reverts to its preformed “memorized” shapeas it advances out of the needle. As shown in FIGS. 78 and 79 theoccluder, when fully released has a shape memory of a pair of spacedspiral coils 802, 804 connected by an intermediate transluminal segment806. The spirals are generally similar and parallel each other exceptthat the wire of one of the spirals overlies the spaces defined by theother spiral as shown, diagrammatically in FIG. 79. The transluminalsegment 806 connects the inner most ends of the spirals 802, 804. It isrelatively short to be able to span and extend through the compressedtissue and to space the spirals so that they engage the outer surfacesof the tissue and constrain the tissues in a serpentine pattern asillustrated in FIG. 80. The serpentine pattern is considered toeffectively secure the tissue layers together with less force than isapplied with a more conventional clamp. In the case of a blood vessel orother tubular body organ the occluder may be effective to occlude flowof blood or other fluid through the vessel. The device is delivered byfirst transfixing the vessel or tissue layers with the needle ofdelivery tube. Then, the distal portion of the wire is advanced out ofthe distal end of the needle or tube. Freed from its restraint, thedistal portion of the wire self expands to the desired shape of thedistal spiral. The needle or tube then is withdrawn to locate its distaltip on the proximal side of the vessel or tissue and then the proximalportion of the wire is released to form the proximal spiral, thetransluminal portion extending transversely through the tissue. The wirecomposition and dimensions may be varied to suit varying anatomicalconsiderations as will be appreciated by those skilled in the art.

In each of the foregoing embodiments the transfixion aperture that isformed by the device does not tend to leak blood (or other fluid)because the zone about the point of transfixion where the legs cooperateto prevent fluid flow substantially prevents fluid from reaching theaperture. Thus, the invention may be advantageous in many situationsover other techniques in which blood loss may be problematic (e.g.,staples, sutures, etc.)

Thus, it will be appreciated that the foregoing description providesdevices and methods for occluding vessels and for clamping tissue layersthat provide advantages over prior art techniques. Occluders and clampsare provided that employ a pair of components that are brought togetheron opposite sides of a vessel or tissue layers to compress the vesselwalls or tissue layers. The clamping may be directly on the tissue ormay be such as to constrain the tissue layers in a serpentine patternthat is considered to occlude or clamp with less direct compressiveforce on the tissue. Applying oppositely directed forces at alternatinglocations on the tissue circumferentially about the center of theoccluder also may effect occlusion or clamping. The occluders mayinclude pluralities of radially extending legs or spirally orientedelements that cooperate to effect occlusion or clamping. In eachinstance a pressure zone of occlusion is formed about the point oftransfixion to prevent leakage through the transfixion aperture.

It should be understood, however, that the foregoing description of theinvention is intended merely to be illustrative and that otherembodiments, modification and equivalents may be apparent to thoseskilled in the art without departing from the principles of theinvention.

1. Apparatus for clamping tissue layers together comprising: a proximalimplant and a distal implant disposed along a common axis, each implanthaving a plurality of radially extending legs; a latching elementassociated with each of the implants to cooperatively secure theimplants to each other such that tissue layers disposed between theimplants may be gripped between the legs of the proximal and distalimplants; the implants, when secured together, being oriented about theaxis with legs of one of the implants being interdigitated with legs ofthe other implant and constrain the tissue in a serpentine configurationthat circumscribes the axis.
 2. Apparatus as defined in claim 1 furthercomprising: each implant having a delivery configuration in which itslegs are arranged in a low profile by which it can be releasablycontained in a delivery tube and an expanded profile in which the legsself-expand to extend radially outward of the axis when released fromits delivery tube, the implants being moveable toward each other whenreleased.
 3. Apparatus as defined in claim 2 further comprising aproximal delivery tube containing the proximal implant and a distaldelivery tube containing the distal implant; a guidewire having aselectively expandable distal tip; a hollow needle adapted to passthrough the tissue layers, the needle containing the distal deliverytube and distal implant, whereby the needle can pass through the tissuelayers to locate the distal end of the distal delivery tube distallybeyond the tissue layers; the guidewire extending through the distalimplant delivery tube and the distal implant; a pushing memberadvanceable through the distal implant delivery tube and engageable withthe proximal end of the distal implant to push the distal implant out ofthe distal end of the delivery tube and enable the legs of the distalimplant to expand distally of the tissue layers, the distal implantbeing retainable on the guidewire by engagement with its expanded tip,the distal delivery tube, pushing member and needle being removableafter deployment of the distal implant; the proximal delivery tube beingadvanceable over the guidewire to place its distal end on the proximalside of the tissue layers, the proximal implant being slidable distallythrough and out of the distal end of the proximal delivery tube by thepushing member to enable the legs of the proximal implant to expand; thepushing member and guidewire expanded tip enabling the proximal anddistal implants to be brought together to enable the latching elementsto engage and secure the implants together with tissue layerstherebetween.
 4. Apparatus as defined in claim 3 further comprising: theproximal implant and pushing member having releasably interlockingelements by which rotation of the pushing member can be transmitted tothe proximal implant, to enable the angular position of the proximallegs about the axis to be adjusted.
 5. Apparatus as defined in claim 3wherein each implant has a tubular portion and wherein the tubularportion of one is receivable, telescopically, into the tubular portionof the other implant when the implants are brought together intoengagement with each other.
 6. Apparatus as defined in claim 1 whereinthe tissue layers comprise opposing wall portions of a hollow or tubularbody part and the serpentine configuration is such as to occlude thehollow or tubular body part.
 7. Apparatus as defined in claim 1 whereinthe latching elements comprise a ratchet mechanism by which theproximity of the implants, when secured, can be varied.
 8. Apparatus asdefined in claim 1 in which the latching elements comprise; one of theimplants having a locking tube extending axially in a proximaldirection; the other implant having a tubular body portion with an axiallumen receptive to the locking tube when the implants are broughttogether; the locking tube and tubular body portion having cooperativedetents that lock the implants together.
 9. Apparatus as defined inclaim 8 wherein the cooperative detents are arranged so that theimplants can be locked together only when their legs are in aninterdigitated orientation.
 10. Apparatus as defined in claim 2 whereinboth of the implants are contained within a single delivery tube intandem relation, the legs of the implants being constrained in a lowprofile by engagement with the lumen of the delivery tube; the distalimplant having a locking shaft secured thereto, the locking shaft havinga first connector element at its proximal end; a retention shaftextending through the delivery tube and having a second connectorelement at its distal end, the first and second connector elements beingcooperatively engageable to releasably lock the locking shaft to theretention shaft; the proximal implant being mounted within the deliverytube and about the one of the retention shaft or locking shaft; thedelivery tube being advanceable through the tissue layers to locate thedistal implant on the distal side of the tissue layers, the distalimplant being exposable by retraction of the delivery tube whilemaintaining the position of the retention shaft; and a pushing memberadvanceable within the delivery tube for engaging the proximal implantand urging it along the retention shaft and locking shaft into lockingengagement with the distal implant.
 11. Apparatus as defined in claim 10further comprising a locking pin removably extending through the lockingshaft and retention shaft to secure the connection therebetween. 12.Apparatus as defined in claim 10 wherein each implant has a tubularportion and wherein the tubular portion of one is receivable,telescopically, into the tubular portion of the other implant when theimplants are brought together into engagement with each other. 13.Apparatus as defined in claim 10 wherein the latching elements provide aratchet by which the proximity of the implants, when secured, can bevaried.
 14. Apparatus as defined in claim 10 wherein the tissue layerscomprise opposing wall portions of a hollow or tubular body part and theserpentine configuration is such as to occlude the hollow or tubularbody part.
 15. Apparatus as defined in claim 10 in which the latchingelements comprise; one of the implants having a locking tube extendingaxially in a proximal direction; the other implant having a tubular bodyportion with an axial lumen receptive to the locking tube when theimplants are brought together; the locking tube and tubular body portionhaving cooperative detents that lock the implants together. 16.Apparatus as defined in claim 2 wherein the legs of the implants, whenin their expanded configurations, are at an acute angle to the axis anddefine, generally, a conical locus.
 17. Apparatus as defined in claim 16wherein the conical loci both face in the same proximal or distaldirection.
 18. Apparatus as defined in claim 16 wherein the conical lociface each other.
 19. Apparatus for clamping tissue layers togethercomprising: a proximal implant and a distal implant disposed along acommon axis, each implant having a plurality of radially extending legs;a latching element associated with each of the implants to cooperativelysecure the implants to each other such that tissue layers disposedbetween the implants may be gripped between the proximal and distalimplants; the implants, when secured together, being configured toalternately apply oppositely directed forces to the tissue layers atcircumferentially spaced locations about the axis of the implants. 20.The apparatus as defined in claim 19 wherein the oppositely directedforces constrain the tissue layers between the implants in a serpentineconfiguration.
 21. Apparatus for clamping tissue layers together asdefined in claim 1 further comprising: the implants having axiallydisposed members by which they can be connected together, at least oneof the axially disposed members extending through a transfixion aperturein the tissue; the implants, when secured together, defining a zone ofocclusion surrounding the transfixion aperture, thereby substantiallypreventing leakage from the transfixion aperture.
 22. Apparatus forclamping tissue layers together comprising: a first coil arranged in aspiral and having a center and spaces between the individual turns ofthe spiral; a second coil having a center and arranged in a spiral thatoverlies the spaces between the individual turns of the first coils; thefirst and second coils being joined at their centers.
 23. Apparatus asdefined in claim 22 wherein the coils are joined by a transluminalsegment connected to each of the centers.
 24. Apparatus as defined inclaim 23 wherein the coils and the transluminal segment are formed froma single, continuous wire.
 25. A method for clamping tissue layerstogether comprising: constraining the tissue layers together by applyingoppositely directed forces to opposite surfaces of the tissue layers,the forces being applied alternately at circumferentially spacedlocations about a central location.
 26. A method for clamping tissuelayers together comprising: constraining the tissue layers together in aserpentine configuration between at least three clamping segments andhaving at least three sequentially reversing bends, the serpentineconfiguration circumscribing an axis that is approximately perpendicularto the tissue layers.
 27. The method as defined in claim 26 wherein thetissue layers comprise opposing portions of a tubular or hollow bodypart and where the clamping occludes the lumen of the body part.